liming

liming (lĪmˈĭng) [key], application to the soil of calcium in various forms, generally as ground limestone, but also as marl, chalk, shells, or hydrated lime. Lime benefits soil by neutralizing acidity, improving texture, and increasing the activity of soil microorganisms. It enables bacteria on the roots of legumes, e.g., alfalfa and clover, to secure essential nitrogen from the air, increasing soil fertility. It also increases the available phosphorus in soils. The value of liming was recognized in ancient Rome, and it was common in medieval France and England. Some 17 million tons of lime are sold annually in the United States. In 1987, 264,000 United States farms applied lime on 12.5 million acres.